These mechanical clocks were intended for two main purposes: for signalling and notification (e.g. the timing of services and public events), and for modeling the solar system. The former purpose is administrative, the latter arises naturally given the scholarly interests in astronomy, science, astrology, and how these subjects integrated with the religious philosophy of the time. The astrolabe was used both by astronomers and astrologers, and it was natural to apply a clockwork drive to the rotating plate to produce a working model of the solar system.
Time switches can be used to turn on anything that will awaken a sleeper, and can therefore be used as alarms. Lights, bells, and radio and TV sets can easily be used.[32] More elaborate devices have also been used, such as machines that automatically prepare tea or coffee. A sound is produced when the drink is ready, so the sleeper awakes to find the freshly brewed drink waiting.[33]
Some clocks, usually digital ones, include an optical projector that shines a magnified image of the time display onto a screen or onto a surface such as an indoor ceiling or wall. The digits are large enough to be easily read, without using glasses, by persons with moderately imperfect vision, so the clocks are convenient for use in their bedrooms. Usually, the timekeeping circuitry has a battery as a backup source for an uninterrupted power supply to keep the clock on time, while the projection light only works when the unit is connected to an A.C. supply. Completely battery-powered portable versions resembling flashlights are also available.

For convenience, distance, telephony or blindness, auditory clocks present the time as sounds. The sound is either spoken natural language, (e.g. "The time is twelve thirty-five"), or as auditory codes (e.g. number of sequential bell rings on the hour represents the number of the hour like the bell, Big Ben). Most telecommunication companies also provide a speaking clock service as well.
A brushed and polished brass finish gives this metal carriage alarm clock its enduring style. The decorative handle, turned brass button feet, and polished brass-tone columns at the corners add to the clock's stately presence. Beneath a glass crystal, the brushed brass-tone dial features circular, diamond-cut numeral ring, black Roman numerals, black hour and minute hands, and brass second and alarm hands.
Bring contemporary and clean-lined looks to your walls with this understated wall clock, this perfect mix of subtle, airy looks and midcentury modern aesthetics in your space. Featuring a simple rectangular metal frame finished in antique brass and distressed gray, this clock brings a warm look to your ensemble, while its elongated Roman numerals offer an updated twist on a classic look. To clean, simply wipe with a damp cloth.
The pendulum is a reliable time measurer because, for small arcs, the time required for a complete swing (period) depends only on the length of the pendulum and is almost independent of the extent of the arc. The length of a pendulum with a period of one second is about 39 inches (990 mm), and an increase in length of 0.001 inch (0.025 mm) will make the clock lose about one second per day. Altering the length of a pendulum is therefore a sensitive means of regulation. The alteration is usually carried out by allowing the bob to rest upon a nut that can be screwed up or down the pendulum rod.
From the 14th century, some clock towers in Western Europe were also capable of chiming at a fixed time every day; the earliest of these was described by the Florentine writer Dante Alighieri in 1319.[8] The most famous original striking clock tower still standing is possibly the one in St Mark's Clocktower in St Mark's Square, Venice. The St Mark's Clock was assembled in 1493, by the famous clockmaker Gian Carlo Rainieri from Reggio Emilia, where his father Gian Paolo Rainieri had already constructed another famous device in 1481. In 1497, Simone Campanato moulded the great bell (h. 1,56 m., diameter m. 1,27), which was put on the top of the tower where it was alternatively beaten by the Due Mori (Two Moors), two bronze statues (h. 2,60) handling a hammer.
This 33" metal wall clock features an antique nickel-finished frame is 7" wide and curves down from the face to the wall hiding the almost 3" in depth. The frame also features 100 decorative nail heads in two rows one on the inside of the frame and one on the outside of the frame.The accurate Quartz movement is operated by one AA battery. One year warranty and Free Shipping.

The Ruggie is made out of fleece and memory foam, which helps you ease into the cruel world that resides outside your duvet-adorned sanctuary. You can also set the device to play custom MP3s once you’ve applied pressure and silenced your alarm. Because, if anything, that stunning achievement deserves a theme song. If you like the idea of no snooze button, but you don’t think the Ruggie would work for you, then check out some of these other alarm clocks that force you to get out of bed.


Who doesn't love an alarm clock that verbally lets you know it's time to get up and start your day? Step aside, Siri, because "Reminder Rosie" is where it's at. You can easily record up to 25 different alarm-reminders at 6 seconds each. So why not wake up to a recording of your kids saying, "Good morning, Mom!"? (Or maybe you don't want that.) We love how you can turn off the alarm by quickly pressing a button or just saying out loud, "Reminder Off." 
This massive iron wall clock is 49" in diameter and is finished in off-white with an antique nickel outer ring that is moderately distressed and dented for an aged appearance. Black Roman numerals are centered on individual antique off-white panels. Quartz, battery-operated movement requires one AA sized battery. Some assembly is required. One year warranty and Free Shipping.

Can we let you in on a secret? From pocket watches to grandfather clocks, a timepiece often tells as much about its owner as it does the hour. With a piece like this, you can ensure that it makes a statement in rustic-inspired style. Crafted from solid rubberwood with black metal spade handles, this piece is full of cottage charm. Featuring a distressed finish and roman numerals alongside its open back, this piece is sure to make welcome guests to your home with its modern farmhouse details.
Get the reliability you need without sacrificing style. Get the reliability you need without sacrificing style. The Analog Quartz Mantel Alarm Clock from La Crosse Clock Co. is a traditional beeping alarm clock. It has the added bonus of luminous hands for easy nighttime viewing. The classic design features a black matted frame with black metal hands and ...  More + Product Details Close
This is the number-one selling kid's clock on Amazon, with more than 2,500 reviews. Parents rave about the restoration of their sleep time. Many parents say it "saved me from my early riser! Life changing!" Even parents of older children with developmental delays found the clock very useful in indicating to non-readers when it's okay to get up, and when it's not.
For light sleepers, audio alarms can be rather jarring. Fortunately, the Philips Morning Wake-Up Light uses a warm, gentle glow and natural sound effects rather than incessant beeping to get you out of bed. The alarm clock also features a colored sunrise simulation and 20 brightness settings for optimal customization. The light slowly increases in brightness between 20 and 40 minutes prior to your desired alarm time. The clock helps you drift to sleep, too. Instead of you simply turning out the lights and settling into bed, the light-responsive dimming feature gently guides you to sleep with audio accompaniment. This type of alarm is definitely not for everyone, but it is suitable for those who prefer to wake up gradually. For more details, read our full Philips Wake-Up Light review.
This oversized aged metal wall clock is 31.5" square and is finished in aged white and gray. The aged dial with aged black Roman numerals and aged black spade hour and minute hands sits behind a glass crystal and is surrounded by a formed metal bezel finished in aged white and gray. Quartz, battery-operated movement requires one AA sized battery (not included). One year warranty and Free Shipping.

This color-changing option features a radio, built-in wake-up tones, Bluetooth music streaming (so you can wake up to your favorite playlist), and USB-charging capacity to keep your phone juiced. You can preset two alarms, cycle through colors, and snooze, and even use the alarm clock's speakerphone and microphone functions to answer phone calls from paired devices. Basically, this clock does everything except your laundry.

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If the last thing you do before closing your eyes for the night is pick up your cell phone to set the alarm, how likely is it that you're just going to do that one thing, then set the phone down on the nightstand? Admit it, you're probably going to check your Instagram, send a text or two, play just one more round of your favorite game, or surf the web.
Showcasing the time, date, and weather, this clock is an essential for any desk. No need to lift your arm and look at your watch or light up your phone screen, this 0.3'' H x 3.7'' W x 1.5'' D design is an easy way to get the info you need. A vibrant blue backlight keeps it illuminated (requiring the power of a AA battery), while a plastic frame allows it to stand upright.

Wallingford's clock had a large astrolabe-type dial, showing the sun, the moon's age, phase, and node, a star map, and possibly the planets. In addition, it had a wheel of fortune and an indicator of the state of the tide at London Bridge. Bells rang every hour, the number of strokes indicating the time.[22] Dondi's clock was a seven-sided construction, 1 metre high, with dials showing the time of day, including minutes, the motions of all the known planets, an automatic calendar of fixed and movable feasts, and an eclipse prediction hand rotating once every 18 years.[23] It is not known how accurate or reliable these clocks would have been. They were probably adjusted manually every day to compensate for errors caused by wear and imprecise manufacture. Water clocks are sometimes still used today, and can be examined in places such as ancient castles and museums. The Salisbury Cathedral clock, built in 1386, is considered to be the world's oldest surviving mechanical clock that strikes the hours.[24]

Need a little extra incentive to pry yourself out of bed? You'll have plenty of it with this no-nonsense wheeled alarm clock. After the first time you press snooze, this unit automatically starts moving away from you, creating enough distance to literally force you out of bed in order to shut it off for good. Plus, it also comes in pastel blue, white, red, and more.


The returned instants from Clock work on a time-scale that ignores leap seconds, as described in Instant. If the implementation wraps a source that provides leap second information, then a mechanism should be used to "smooth" the leap second. The Java Time-Scale mandates the use of UTC-SLS, however clock implementations may choose how accurate they are with the time-scale so long as they document how they work. Implementations are therefore not required to actually perform the UTC-SLS slew or to otherwise be aware of leap seconds.


This SmartSet Alarm Radio with Bluetooth Speaker Desktop Clock is a thing of the past. The digital tuning clock radio automatically sets itself on the first use to the correct year, month, date, day, and time. The clock radio features Bluetooth v4.1 digital tuning FM radio. Includes a USB output for mobile charging (2.1a 5V) and a large and easy-to-read LED display. The alarm can be programmed to operate on weekdays only, weekends only, or all seven days of the week. Set the alarm to wake you...
“This alarm clock will wake you up! I’m totally deaf in one ear and partially deaf in the other. Alarm clocks I used before I purchased this one might as well have been turned off if I happened to have my good ear on the pillow when they went off. This one is loud! Now having said that, its loudness is adjustable, and I found that a low setting of two works just fine for me, but if I am particularly concerned about being awakened, I also set the vibrating disk, which is slipped under the mattress. Believe me: Even if you are totally deaf in both ears, this will wake you up. I was skeptical about the vibrator because I have a thick mattress, but it works with no problem at all! I wholeheartedly recommend this alarm clock for anyone who is hearing impaired.”
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